Volumetric imaging has become an integral part of modern medicine. Such imaging has been widely used to not only diagnose disease but as an aid in administering medical treatments. When using diagnostic probes, operating instruments or radiation therapy, a medical professional can be greatly aided by images taken of the patient that can identify target areas, or areas to be avoided.
For example, cone-beam computed tomography (CBCT) instruments have been coupled to X-ray delivery devices to provide in situ clinical imaging and radiation therapy simultaneously. The Elekta Synergy™ system is an example of a commercially available system that combines imaging and delivery into one integrated treatment system for precise delivery of radiation therapy.
Although the integration of imaging systems with delivery systems has many advantages, there is at least one drawback. Both imaging systems and delivery systems have components that move, typically in a circular motion. When imaging and delivery systems are integrated, motion of the components is less stable than the separate systems, resulting in perturbations from ideal behavior.
Such perturbations denigrate performance. For example, in cone beam tomography, non-ideal motion, such as tilting or twisting of the image device, can produce severe artifacts, such as loss of detail, poor registration, and streak artifacts. In the delivery system, perturbations can cause inaccurate delivery of energy to a part of the body. Therefore, any system or method that can account for non-ideal motion would be most welcome.